Circuit-breaker



I. P. ARNDT cmcun BREAKER.

I APPLICATION FILED NOV. I5, I9I?. 1,366,343. Patented Jan. 25, 1921.

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CIRCUIT-BREAKER.

Specification of Letters Patent.

Patented Jan. 25, 1921.

Application filed November 15, 1917.` Serial No. 202,108.

T all yw/tom 'it may concern:

Be it known that I, JOHN I. ARNDT, a citizen of the United States, and resident of Milwaukee, in the county of Milwaukee and State of VVisconSin, have invented new and useful Improvements in Circuit-Breakers, of which the following is a description, reference being had to the accompanying drawings, which are a part of this specification.

The invention relates to automatic circuit breakers.

The invention is more particularly designed to provide a magnetically released circuit breaker `for high potential work whereby mechanical separation of two con'A tacts is controlled by an electro-magnet to open the circuit under excessive loads.

The invention is further designed to provide a simple and effective means operated on the separation of the contacts to shoot a stream of air between the contacts to extinguish the arc and prevent damage to the contacts.

The invention further consists in the several features hereinafter set forth.

In the drawings:

Figure 1 is a vertical sectional view with part in elevation through the device embodying the invention;

Fig. 2 is a section taken on the line 2--2 of Fig. 1.

In the drawings the numeral 3 indicates the casing of insulating material consisting of a .main cylindrical portion 4 and a cylindrical portion 5 disposed at one side of the main portion. The portion 4 is provided with a bore 6 extending to a shouldered portion 7, said portion 7 having a centrally disposed aperture 8 therein. The top of the portion 4 is provided with upwardly. and laterally projecting radially disposed arms 9 upon which a cap 10 is fitted, the arms forming open spaces 11 between the casing and the cap to establish communication between the space inclosed by the cap and the outside air. A conductor conduit 12 is formed integral with one of the arms 9. The portion 5 is provided withI a bore 13 and a conductor conduit 13 integral with the casing communicates with this bore. An end plate 14 is secured to the bottom of the casing and closes up the ends of the bores 6 and 13.

Mounted within the bore 6 between the shouldered portion 7 and an apertured insulating washer 15 is a metal cylinder 16 having a lengthwise extending recess 17 forming a by-pass as hereinafter described.

. Shdably movable within the cylinder 16 1s a piston 18 having an annular recess 19, a central tubular portion 20 and radially ertending passages 21 connecting the interior of the tube 20 with the space formed by the recess 19 between the cylinder 16 and the piston. The end of the piston has a centrally disposed threaded aperture 23 in which a threaded plug 24 of insulating material is mounted, a rod 25 being secured to said plug and'being slidably mounted in an aperture 26 in the end plate 14. Tlhe piston 18 is provided with a bore 27.

A fire tube 28 fits within the aperture 8 of the casing and extends down into the bore 27, said tube having an annular flange 29 seated in an annular recess 30 in the casing.

Seated within the bore 27 and surrounding the tube 28 and bearing against the shouldered portion 7 of the casing is a compressible' coiled spring 31 which normally tends to move the piston 18 toward the bottom of the cylinder 16 to compress the air in the closed end portion of the cylinder.

The separable contacts consist of a fixed contact carried by the casing and a movable contact carried by the piston.

The fixed contact consists of spaced apart metal half sleeves 32 yieldingly secured to arms 33 by a; yielding yoke 34 formed of metal bands. The arms 33 are secured to the top of the casing by bolts 35 which pass through the shouldered portion of the Casin and through the flange 29 of the tube. conductor 36 which passes through the conduit 12 is secured to the yoke 34 by a binding screw bolt 37.

The movable contact consists of a metal tube 38 secured to the tubular portion 20 of the piston 18 and adapted to be slidably engaged at its upper end by the sleeve contacts 32. In order to minimize arcing on the separation of the contacts I provide a metal sleeve or arcing contact 39 slidably mounted upon the tube and having a flared upper end 40 adapted to contact with the bottom of the sleeves 32 and a slot 41 therein to allow for expansion and contraction, said sleeve being secured t0 a collar 42 mounted upon the tube 38. A coiled spring 43 surrounding a portion of the tube 38 is secured to the collar 42 and the portion 20 of the piston whereby said sleeve 39 is normally held in contact with the sleeves 32.

The electro-magnetic means for control-1k ling the circuit breaker consists of a solenoid for releasing the detent 44 from engagement with the collar 46.

The solenoid consists of a coil 52 disposed within the bore 13, a sleeve 53 and the sleeve i 48 mounted within the sleeve 53 and forming the core of the solenoid. The movement of the core 48 upon the rod 50 is limited b. nuts 54 on the lower end of said rod. line conductor 55 passes through the conduit 13 and is connected up to one end of the coil and the other end 56 of the coil passes through a slot 57 in the casing and is soldered or otherwise suitably connected tothe cylinder 16.

With this construction the circuit breaker is set in working position by moving the piston 18 and rod 25 upwardly within the cylinder by pushing upon an insulated handle 58 until the detent 44 engages the collar 46 as shown in Fig. 1. Under these conditions the current passes through the conductor 55, coil 52, cylinder-16, piston 18, the movable contact or tube 38, the iixed contact or sleeves 32, yoke 34 and the conductor 36. Under ordinary working conditions the solenoid is so designed as not to affect the core but when the magnitude of the current in the line becomes so great that it is necessary to open the circuit, the excessive current through the coil 52 causes the armature core 48 to move upwardly, the flange 48 on said member engaging the lever 44 and moving it upwardly to release the hooked end 45 from the collar 46 with the result that the spring 31 pressing upon the piston 18 moves it downwardly together with the tube 38 which moves out of contact with the sleeves 32. As there is relative sliding movement betwen the tube 38 and the sleeve 32, the contact 39 is held up against the sleeves 32 until the tube 38 breaks the main contact, thereby diminishing the are.

As the piston 18 propelled by the spring 31 moves downwardly it compresses the air below it in the cylinder 16 and when the recess 19 comes into communication with the slot or by-pass 17, the compressed air beneath the piston passes through said by-pass into the space formed by the recess 19, through the passages 21 up the tube 38, the

air passing out through the tube in a stream as the tube 38 and sleeve 39 separates from the fixed contacts, the passage of the air disrupting and extinguishing the arc and thereby preventing damage tothe contact points, the air passing from the tube into the space beneath the cap 10 and out through the spaces 11.

The invention thus exemplifiesl a simple, compact and efficient means for extinguishing an arc by blowing a current of Iair across the contacts, the current of air being produced within the device itself.

The invention further exemplifies a simple form of magnetically released circuit breaker.

I am aware that the details of construction herein shown and described are capable of vsome modification and change and I desire it to be understood that such changes in construction as come within the scope of the appended claims I deem to be within the spirit of my invention.

Vhat I claim as my invention is:

1. In a circuit breaker, the combination of a cylinder having a closed end. a piston working within the cylinder, a fixed contact, a tubular Contact carried by the piston and engageable with the fixed Contact to complete a circuit, means for moving the piston to separate the contacts and compress the air in the closed end of the cylinder, and means for conducting the compressed air from the closed end of the cylinder through the tubular contact after the piston has completed a portion of its movement in the cylinder to separate the contacts.

2. In a circuit breaker, the combination of a cylinder having a closed end, a piston working within the cylinder, a fixed hollow contact, a movable hollow Contact carried by the piston, means for moving the piston to separate the contacts and to compress air in the closed end portion of the cylinder, means for conducting the compressed air in the cylinder through the piston and to the hollow of the movable contact after said piston has had an initial movement in the cylinder, and controlled means for releasably maintaining the movable contact in engagement with the fixed contact.

3. In a circuit breaker, the combination of a cylinder having a closed end, a piston working within the cylinder, a fixed contact, a movable contact carried by the piston and engageable with the fixed contact to complete a circuit, means for moving the piston to separate the contacts and compress the air in the closed end of the cylinder, said. contacts not separating until the piston has had a predetermined movement under the action of said means, and means for conducting the compressed air from the closed end of the cylinder onto the contacts upon the piston reaching a predetermined point in the cylinder while moving -under action of said means for moving the same.

4. In a circuit breaker, the combination of a cylinder having a closed end, a piston working within said cylinder, a 'fixed hollow contact, a movable hollow contact carried by the piston, means within the cylinder for moving the piston to separate the contacts and to compress the air in the closed end portion of the cylinder, a passageway in the piston leading from the hollow contact to the wall of the cylinder, a by-pass in the cylinder wall for conducting the compressed air in the cylinder to the passageway in the piston on the separation ot' the contacts, and releasable means for maintaining the piston and its contact in circuit 'closing position.

5. In a circuit breaker, the combination, with a casing, of a cylinder within the casing and having a closed end, a piston work ing within said cylinder, a fixed hollow contact on the casing, a movable hollow contact carried by the piston, a spring within the cylinder for moving the piston to separate the contacts and to compress the air in the closed end portion of the cylinder, means for conducting the compressed air in the cylinder through the piston and to the hollow of the movable contact, and means Jfor releasably maintaining the piston and its contact in circuit closing position.

6. In a circuit breaker, the combination, with a casing, of a cylinder within the casing and having a closed end, a spring actuated piston working within the said cylinder for compressing the air in the closed end portion of the cylinder, a fixed hollow contact on the casing, a movable hollow contact.

carried byl the piston, means for conducting the compressed air in the cylinder through the piston and to the hollow of the movable contact on the movement of the piston to separate the contacts, a chamber within the casing juxtaposed to the closed end of the cylinder, and means in said cylinder for releasably maintaining the piston and its contact in circuit closing position.

7. In a circuit breaker, the combination,

, with a casing, of a cylinder within the casing and having a closed end, a piston having a bore therein and working within said cylinder, a fire tube carried by the casing and extending into said bore, a compressible spring disposed within the bore and surrounding said tube for moving the piston to compress the air in the closed end portion of the cylinder, a fixed hollow contact on the casing, a movable hollow contact carried by the piston, means for conducting the compressed air in the cylinder to said movable .hollow contact on the separation of the contacts, and automatically1 releasable means for maintaining the spring in compressed condition and the movable contact in engagement with the ixed contact.

8. In a circuit breaker, the combination, with a casing, of a cylinder within the casing and having a closed end, a spring actuated piston in said cylinder for compressing air in the closed rend portion thereof and having an annular recess, a contact tube carried by the piston, passageways leading from the recess to said tube, a by-pass in the cylinder wall, a fixed contact, means normally securing said'piston against actuation, and controlled means for releasing said securing means to permit actuation ot the piston to separate the contacts and torce the compressed air through the contacts on their separation to disrupt the arc.

9. In a circuit breaker, the combination, with a casing, of a cylinder within the casing and having a closed end, a piston having a bore therein for working within the cylinder and having an annular recess, a lire tube carried by the casing and extending in said bore, means disposed within the bore of said piston and surrounding the lire tube for moving the piston to compress air in the closed end portion oit the cylinder, a contact tube carried by the piston, passageways leading from the recess to said tube, a bypass in the cylinder wall, a iixed Contact, means normally securing said piston against actuation, and means for releasing said securing means to permit actuation of the piston to separate the contacts and force the air compressed in the closed end portion of the cylinder through the by-pass in the cylinder wall, the annular recess and passageways of the piston and through the contacts on their separation to disrupt the arc.

In testimony whereof, I aiiix my signature.

- JOHN P. ARND'I. 

